A dream flight to Singapore was spoiled after BA overbooked its flight - This content is subject to copyright.

A woman and her mother who won two business class flights to anywhere in the world missed out on a once-in-a-lifetime chance to fly in luxury when British Airways oversold the flight and bumped the pair down to a lower grade cabin.

Jessica Lowrey, who won the competition run by Flight Centre last year, arrived at London Heathrow with her mother, Laura, for a flight to Singapore in Club World, but sensed something was wrong when they were unable to check in at an automated kiosk and had to join a queue at a manned desk.

“This was when we started to worry,” said Jessica, who decided to use the prize to take her mother to Bali, via Singapore, for a two-week holiday. “We overheard a woman telling a family that BA had oversold their flight to Oslo... and I thought ‘how can they oversell flights?’

“We eventually got to the front and a woman scanned our coupons (which we had been given at the kiosk). She called someone and was silent for what felt like 15 minutes. We could tell bad news was coming.”

The member of staff then told the mother and daughter that the flight had been oversold and that there were no Club World seats available so they had been “downgraded” to Premium Economy.

The Club World cabin on the A380, which serves the Singapore routeCredit: British Airways

“I was just in disbelief,” said Jessica. “Probably the one chance in our lives to fly in luxury and we weren’t able to because BA had oversold. We went from buzzing excitement to utter disappointment.”

Passengers in Club World experience seats that convert into fully flat beds as well as White Company bedding, lavish three-course meals and a wide range of complimentary drinks. Premium economy - or World Traveller Plus - provides guests with wider seats and a little more legroom.

The couple were later told at the gate by two airline staff that as they were “guests of BA” they would be the first to be bumped and would not receive compensation. Paying customers would have been offered cash or an alternative flight.

“We got on the plane and were sat directly behind Club World which was a bit of a kick in the teeth. Being able to see, almost touch, what we could have had,” said Jessica.

British Airways says that it simply provides flights to Flight Centre, which ran the competition, and that it clearly states in the terms and conditions that promotional travel is not guaranteed in the requested cabin.

A spokesperson said: “With the flight being extremely busy we asked two customers to move to our World Traveller Plus cabin. We look forward to welcoming them back on board in Club World on their return.”

A spokesperson for Flight Centre said: “Flight Centre has been made aware of this issue and is looking into the matter as a priority. We are currently investigating the circumstances surrounding this event. Flight Centre takes customer satisfaction extremely seriously and once all necessary details have been confirmed we shall be in contact with the customer.”

Why do airlines overbook flights?

Airlines bank on a percentage of passengers not showing up for their flight and double book seats accordingly. Their sums are based on statistics that are analysed by computer models; often they get it right, sometimes they don’t.

It’s legal for airlines to overbook flights and the practice is more common than you might think. In fact, in the US, which provides the best statistics on the subject, the chance of a passenger being denied boarding because of overbooking is 1 in 1,000.

The vast majority of passengers who are bumped are willing volunteers, encouraged onto another flight by the prospect of compensation or an upgrade.

“Compensation varies from £250 to £600 depending on the length of the delay and the distance of the flight, although an airline is allowed to negotiate a lower rate with those who volunteer to be bumped,” explained Nick Trend, Telegraph Travel’s consumer expert.

Signing up for frequent flier programmes is one way to decrease your chances of being bumped. Flying off-peak and early in the morning will also help.